The auxiliary heating equipment of the present invention may be employed in conjunction with heating systems of different types, including hot water, hot air and steam heating systems. While the embodiment illustrated and described herein is specific to a hot water heating system, it is appreciated that this is shown for purposes of illustration only and without limiting intent, but could equally well have been shown in conjunction with another conventional type of heating system.
As is well known to those versed in the field of heating, high stack temperatures represent substantial loss of heat to the atmosphere, at considerable cost to the user. While many heating systems are represented as having stack temperatures of 470.degree.-570.degree. Fahrenheit, in practice it has been found not unusual for stack temperatures to be about 830.degree. Fahrenheit.
Also, prior art heating systems usually utilized inside air for combustion, which required a substantial flow of combustion air usually through leakage, thereby preventing draft-free weather stripping.
Also, conventional heating systems usually required relatively high combustion or burner temperatures in order to obtain the required amount of heat from the relatively small quantity of fast moving air. This procedure was, of course, thermally inefficient, not only by stack losses, but also by excessive furnace radiation and conduction.